I have not found "Dexagen" in the list of drugs registered in Poland, if you want to ask about Dexaven, please read on. Otherwise, please clarify the question.

After a single injection of Dexaven (8mg), there are no absolute contraindications to hair dyeing. However, because glucocorticoids can affect the skin, causing it to thin or become more sensitive. Dexaven has a long-lasting effect, it is recommended to wait at least a few days (3-5 days) after the injection to make sure there are no skin reactions or other side effects that could be exacerbated by hair coloring.

During this time, you should monitor for skin reactions. In case of any doubts or previous skin problems, it is advisable to consult the attending physician before starting the dyeing.

If you are unable to consult your doctor, you can use the teleconsultation here:

https://www.gdziepolek.pl/telekonsultacja